public class Whale extends Mammal {

    private String pod;
    
    public Whale() {
        super("Whale", "whistle", 3);
        pod = "unknown pod";
		System.out.println("whale constructor (0 parameters)");
    }
    
    public Whale(String pod) {
        super("Whale", "whistle", 3);
        this.pod = pod;
		System.out.println("whale constructor (1 parameter)");
    }
    
    public Whale(String pod, String species, String sound, int gestationPeriod) {
        super(species, sound, gestationPeriod);
        this.pod = pod;
		System.out.println("whale constructor (4 parameters)");
    }

    public String toString() {
        String s = super.toString();
        s += ":" + pod;
        return s;
    }
    
    public void reproduce() {
        System.out.println("birth in ocean");
    }
}